* {@code Iterable}. Except as noted, each method has a corresponding {@link Iterator}-based method
 * in the {@link Iterators} class.
 *
 * <p><b>Java 8+ users:</b> several common uses for this class are now more comprehensively
 * addressed by the new {@link java.util.stream.Stream} library. Read the method documentation below

import com.google.common.primitives.Longs;
import java.util.Comparator;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * A utility for performing a chained comparison statement. <b>Note:</b> Java 8+ users should
 * generally prefer the methods in {@link Comparator}; see <a href="#java8">below</a>.
 *
 * <p>Example usage of {@code ComparisonChain}:
 *
 * <pre>{@code
 * public int compareTo(Foo that) {

/**
 * A comparator, with additional methods to support common operations. This is an "enriched" version
 * of {@code Comparator} for pre-Java-8 users, in the same sense that {@link FluentIterable} is an
 * enriched {@link Iterable} for pre-Java-8 users.
 *
 * <h3>Three types of methods</h3>
 *
 * Like other fluent types, there are three types of methods present: methods for <i>acquiring</i>,

 * existing users, but it can't *fix* existing users because any users who needed
 * `Function<@Nullable A, @Nullable B>` already had to find a workaround. Still, there is a *ton* of
 * fallout from trying to switch. I would be shocked if the switch would offer benefits to anywhere
 * near enough users to justify the costs.
 *

   *
   * <p><b>Java 8+ users:</b> use {@link Integer#toUnsignedString(int)} instead.
   */
  public static String toString(int x) {
    return toString(x, 10);
  }

  /**
   * Returns a string representation of {@code x} for the given radix, where {@code x} is treated as
   * unsigned.
   *
   * <p><b>Java 8+ users:</b> use {@link Integer#toUnsignedString(int, int)} instead.
   *

@ElementTypesAreNonnullByDefault
public final class Functions {
  private Functions() {}

  /**
   * A function equivalent to the method reference {@code Object::toString}, for users not yet using
   * Java 8. The function simply invokes {@code toString} on its argument and returns the result. It
   * throws a {@link NullPointerException} on null input.
   *
   * <p><b>Warning:</b> The returned function may not be <i>consistent with equals</i> (as

@ElementTypesAreNonnullByDefault
public final class Functions {
  private Functions() {}

  /**
   * A function equivalent to the method reference {@code Object::toString}, for users not yet using
   * Java 8. The function simply invokes {@code toString} on its argument and returns the result. It
   * throws a {@link NullPointerException} on null input.
   *
   * <p><b>Warning:</b> The returned function may not be <i>consistent with equals</i> (as

   * @since 33.2.0 (available since 22.0 in guava-jre)
   */
  @SuppressWarnings({"AndroidJdkLibsChecker", "Java7ApiChecker"})
  @IgnoreJRERequirement // Users will use this only if they're already using streams.
  @Beta // TODO: b/288085449 - Remove.
  public static <T extends @Nullable Object> Collector<T, ?, List<T>> least(
      int k, Comparator<? super T> comparator) {
    checkNonnegative(k, "k");

   * @since 33.1.0
   */
  @Beta // only until we're confident that Java 8+ APIs are safe for our Android users
  @J2ktIncompatible
  @GwtIncompatible // java.time.Duration
  @SuppressWarnings("Java7ApiChecker") // no more dangerous that wherever the user got the Duration
  @IgnoreJRERequirement
  public static <T extends @Nullable Object> Supplier<T> memoizeWithExpiration(

  }

  @SuppressWarnings("unused") // compilation test
  public void testSampleCodeFine2() {
    FluentIterable<? extends Number> numbers = getSomeNumbers();

    // Sadly, the following is what users will have to do in some circumstances.

    @SuppressWarnings("unchecked") // safe covariant cast
    Optional<Number> first = (Optional<Number>) numbers.first();
    Number value = first.or(0.5); // fine
  }